Bin feed mechanism



Dec. 7,1943. N. M. LOWER BIN FEED MECHANISM 3 Sheets-Sheet 1 Filed Dec. 6, 1940 INVENTOR N; M; LOWER BIN FEED MECHANISM 3 Sheets-Sheet 2 Filed Dec. 6, 1940 IN 'NTOR (ATTO NEY 5 BIN FEED MECHANiSM FiledDec. e, 1940 3 Sh'eets-Sh eet :s

INVENTOR.

ATTORNEY.

Patented Dec. 7, 1943 anaisi iJlii'iED: stares ram; OFFICE,

2,336,181 BIN FEED MECHANISM Nathan M. Lower, Erie, Pa. Application December 6, 1910, Serial No. 368,880

17 Claims. ,Cl. 198-64) This invention relates to conveying means for removing solid material, particularly coal, from a material containing bin.

Coal, for example, does not flow like water to a lever surface but assumes an angl or" repose of about 45, so that a storage bin will not entirely empty through a singl discharge opening unless the portion of the coal beyond the angle of repose is moved toward the discharge opening by means other than gravity. In automatic stokers, it has been common to use a, screw conveyor to feed coal from a source of supply to a furnace. The source, however, has generally been a hopper of limited size which has to be replenished from time to time from a storage bin.

The storage bins are generally of rectangular shape having a capacity of fifty tons or more of coal, so that even a screw conveyor, disposed in such a bin, would remove only a limited amount of the coal. Frequently too, particularly when the coal is wet, the screw conveyor will merely dig a tunnel through the coal and thereafter run idly.

It is an object of my invention to provide new and improved means for removing the greater portion of the material from a storage bin, regardless of size, through a single discharge epening.

Another object is to provide means, of the type described, that is simple in construction and does not very materially decrease the capacity of the bin.

Another object of the invention is to provide apparatus of the type described that is conveniently accessible for purpose of making repairs,

without it being necessary to shovel any of the material out of the bin, even when the latter is entirely filled.

More specifically an object of the invention is to make substantially all the material in a storage bin available for rernoval bya screw conveyor through a single discharge opening.

Still another object of the invention resides in relieving the conveying means of the greater part of the weight of the head of coal in the storage bin, thereby minimizing stalling of the conveyor and permitting operation of the conveyor with a minimum application of power, while at the same time making most of the coal in the bin available to the conveying means.

The above and other objects and advantages of the invention will be apparent from the following description when read in connection with the accompanying drawings, in which Fig. 1 is a plan View of the bin with the invention in position therein, parts of both being brokenaway;

Fig. 2 is a sectional view taken on the irregular line 2-2 of Fig. 1, parts being broken away;

Fig. 3 is a. sectional view taken on the line 33 of Fig. 2; and.

Fig. 4 is a sectional view taken on the line4 4 of Fig. 1, parts beingshown infull.

While the invention iscapable of general application, it is particularly adaptable to a' coal bin for conveying'coal therefrom directly to astok'er for a furnace. In thepast, stokers have been provided with a hopper or bin of limitedcapacity and it was, therefore, necessary to manually transfer coal from the main storage bin to the auxiliary bin or hopper.

The difficulty in the past in applying the conveying portion of a Stoker, particularly a screw conveyor, directly to th storage bin has been the inability to make a suflicient amount of the coal in the bin available to the conveying mechanism. Other difficulties attendant to placing the transfer conveyor'screw directly in the storage bin have been the problem of relieving the screw of the'weight of the coal while at the same time making the coal available tothe screw conveyor, also making the conveying mechanism accessible for repairs without having to shovel the coal over the sides of the storage bin.

In the drawings, a rectangular shaped bin is shown at It, this being the most common form of bin. The novel train of mechanism is desi nated as a whole by the numeral H and it extends longitudinally and centrally along the ilttom of the bin for the greater part of the length thereof.

The front wall 12 of the bin it is provided with an opening 13 and within the .bin ill and registering with opening [3 is a housing M. The housing [4 is divided into an upper compartment 35 and a lower compartment iii by a transverse horizontal wall l1. The lower compartment i5 is enclosed by the horizontal wall ll, sidewalls l8 and I9, and the rear wall 283, the front being open to permit convenient access to the mechanism disposed therein. The upper compartment 55 or the housing I ,4 is provided with a topwall 2| sloping rearwardly and downwardly from the front wall l2 of the storage bin ill, and side walls 22 and 23 terminating, for a reason to be explained hereinafter, a certain distance abovethe horizontal wall I! providing passages 8 and it.

The top wall 2| is divided "into a stationary front portion 24 and a rear portion 25 arranged to slide longitudinally in guideways 26 and 2'1 ing 34 secured to the rear wall 25 ported from the rear wall 33 of the compartment 29 by a bracket 35 and at its other end in a bearof the compartment l5.

The screw conveyors 35 and Si are operativelyconnected by means of a shear pin 36,,so

that if some foreign material in the coal'should stall the screw conveyor 3|, the shear pin 36 will be sheared off and the screw conveyor 30 will continue to operate and advance the coal for wardly that lies in the forward portion of the storage bin. It is of course understood that the screw conveying system is operated from the forward end of the screw conveyor 38 by any suitable power means.

The flights of the screw conveyors 30 and 3| have a uniform diameter throughout. In order to prevent an accumulation of coal at the forward end of thescrew conveying system, the flight of the screw conveyor 3| is arranged with a greater pitch than the flight of the screw conveyor 38. The screw conveyor 3! will, therefore, advance coal at a slower rate than the screw conveyor 3i and prevent a gradual accumulation of coal in the front conveyor screw 30.

The screw conveyors 30, 3|, alone, working in the bin would act on an insufficient amount of the coal, since coal unlike water or other liquid will not flow but will assume an angle of repose of about 45. This would leave a large amount of dormant coal and necessitate frequent filling of the storage bin. In fact, when the coal is wet there is a tendency for a tunnel to be formed in the mass of coal, so that very little coal would'be advanced by the conveyor screws. In order to make the most of the coal in the storage bin available to the screw conveyorarotating arms 31 and 3B are provided. These arms 3! and 38 rotate in a horizontal plane above the screw conveyors 3E! and 3|, respectively, and push. the coal into the zone of action of the screw conveyors.

' The arms 31 and 38 are secured in any suitable manner to the upright shafts 39 and 40, respectively, mounted in the bearings 4| and 42, respectively. The lower ends of the shafts 39 and to extend into the compartments I6 and 29, respectively, and ratchet wheels 43 and 44 are secured to the lower ends of shafts 39 and 40, respectively, within the compartments l6 and 29, respectively.

A reciprocating rod 45 extends rearwardly from a source of power into the compartment IS. The rod 45 is provided at its rearward end with a pin d6 engaging the teeth of the ratchet wheel 43, and a spring 41 attached to the rod 45 and a part of the housing l4 holds the pin 45 in yield able engagement with the ratchet wheel 43. Thus, upon forward movement of the rod 45, the ratchet wheel 43 is moved a portion of a turn in a clockwise direction, and consequently also the arm 31, and upon rearward movement of the rod 45, the pin 46 slides over the teeth of the ratchet wheel 43.

Similarly, a reciprocating rod 48 extends rearwardly from a source of power through the compartment IS, the tube 49 and into the compartment 29. The tube 45 provides protection for the rod 48 from the coal in the storage bin and together with the tube 59 forms a spacing means between the compartments I6 and 29 and provides for greater rigidity of the compartment 29. The rod 48 is provided at its rearward end with a, pin 51 engaging the teeth of the ratchet wheel 44, and a spring 52 in the tube 49 pushes against the rod 48 and holds the pin 5'! in yieldable engagement with the ratchet Wheel 44. Thus, upon forward movement of the rod 48, the ratchetwheel 44 is moved a portion of a turn in a clockwise direction, and consequently also.

the arm 38, and upon rearward movement of the rod 43, the pin 5! slides over the teeth of the ratchet wheel 44.

The reciprocating rods 45 and 48 may be operated by separate power means or the same power means with suitable clutch mechanism whereby both rods may be operated simultaneously or either one independently of the other. Thus, when coal is being removed from the rear of the bin ID, the rod 48 alone, and therefore, arm 33 alone may be operated; while when coal is being removed from the front of the bin 10, the rod 45 alone, and therefore, arm 3'! alone may be operated.

One of the characteristics of a screw conveyor operating in a mass of material is that it will remove the material at the rearward end of the screw conveyor first, gradually removing the material in the bin from back to front. In the instant case, with the novel coal conveying mechanism in operation, the arm 33 pushes the coal in the rearward portion of the storage bin into the zone of action of the screw conveyor iii. The arm 38 thus makes an inverted truncated cone-shaped mass of coal available to the screw conveyor 3| for advancement in and removal from the bin. The inverted truncated cone would have a base equal to the area traversed by the arm 38 and flare outwardly at an angle of about 45 as it extends upwardly, the angularity being determined by the angle of repose of the material in the bin. Referring to Fig. 2, the amount of material removed from the bin by the screw conveyors in conjunction with the arm 38 is represented by the letters a, a.

The screw conveyor 30 in conjunction with the arm 31 will remove a similar inverted truncated cone-shaped mass of coal from the bin, represented in Fig. 2 by the lines identified with the letters b, b. It is apparent, then, that the two arms 31, 58 in conjunction with the screw conveyors 3i), 3! will remove the greater portion of the coal from the storage bin l0.

As stated above the screw conveying means 35, 3| will remove the coal from the rearward portion of the bin first. It will be apparent there, that if the full head of coal is permitted to rest on the front portion of the screw conveying means, considerable power is necessary to rotate the screw conveyor since the coal that is being advanced from the rear of the conveyor is being forced against the coal that is resting between and on the flights of the forward portion of the screw conveyor. The roof 2| of the housing 14 prevents the head of coal from resting on the front conveyor screw 30 and a horizontal plate 60 extending rearwardly from the rear-wall 20 of housing (4 over the forward portion of the rear conveyor screw 3| prevents the coal from resting on the forward portion of this screw.

The plate 60 is disposed in a plane above the plane of the arm 38, and the width of the plate and distance above the screw conveyor are so related that the coal upon assuming its angle of repose, will stop just short of the screw conveyor 3!. Thus the coal being conveyed from the rearward end of thebin will not encounter a head of coal during its advancement.

The openings in the sides of the housing M between the lower edges of the side walls 22, 23 and the transverse plate I! are of a height so that the coal entering therethrough by gravity will upon assuming its normal angle of repose,

represented in Fig. 3 by the letter X, leave aclear space extendin longitudinally and centrally through the compartment l sufficiently large to permit a man to crawl therethrough 1 when necessary to make repairs.

A serious objection to the use of conveying mechanism beneath a mass of coal has been the inaccessibility of the mechanism for purpose of repair at times when it gets out of order. The present invention obviates the necessity of shoveling the coal over the sides of the bin to obtain access to the conveying mechanism when it fails.

Should the screw conveyor 3! stall by reason of foreign material in the coal or for other causes, the shear pin 36 will shear ofi permitting the continued operation of the screw conveyor 3c. The screw conveyor 35! in conjunction with the arm 37 will then remove the coal in the forward portion of the bin. When the forward portion the bin is emptied, it is a simple matter then, to shovel the coal from the rear portion of the bin to the forward portion thereof until the conveying mechanism at the rear is accessible. Thus, continuity of operation is not broken and the labor and trouble of shoveling the coal over the side of the bin and then back into the bin after repairs have been made is avoided.

Access to the forward screw conveyor 39 for purpose of repair is gained through the opening l3 and the housing I i, the latter being of sufficient size to permit a man to crawl therein. In normal operation, as stated before, the screw conveying system removes the coal from the rear portion of the bin, after which the coal is removed from the front portion of the bin. The coal in the front portion of the bin enters the compartment I l beneath the side walls 22 and 23, the arm 31 pushing the coal into the trough 28 where the screw conveyor 353 carries it forwardly out of the bin. Coal is also admitted to the housing M through the top thereof by sliding the rear portion 25 of the top wall 2| forwardly beneath the stationary front portion 24. Any suitable means may be used to move the rear portion 25 of the top wall 21 forward and backward. As shown, the rear portion 25 is provided with a lug 53 having a threaded opening, and a threaded rod 56 is threaded in the lug 53 and extends forwardly through the opening i3. By turning the rod 54 in one direction, the top wall portion 25 is moved forwardly and by turning the rod 55 in the opposite direction, the top wall portion 25 is moved rearwardly.

Should the forward portion of the conveying mechanism fail for any reason, access may be had thereto by moving the top wall portion 25 rearwardly, thereby preventing coal from entering the housing M throughthe top thereof and shoveling out the small amount of coal in the housing M. The openings in the sides of the housing M between the side walls 59 and 23 and the side walls 18 and 22 are such that the coal entering therethrough will not when it as sumes its normal angle of repose, cover the central portion of the horizontal wall ll.

Since the screw conveying system first removes the coal from the rearward end of the bin, the plate 68 may be terminated short of the rearward-end of the screw. However, if it is desirable to still further reduce the power necessary to operate the screw conveying system, the plate Bil may be extended farther rearward to keep the weight of the coal off the rearward portion of the screw conveyor 5!.

The housing l i'also serves to keep the weight of th head of coal in the bin off the rotating arm 37, thereby eliminating stalling of the arm 31 and minimizing the power necessary to rotate the arm 3?. The coal entering the housing I4 through the passages 6 and 9, as best shown in Fig. 3, to its angle of repose X bears on the arm 3'! with a weight that is insignificant as compared with the weight, were the arm to rotate in the mass of coal itself. The arm 3'. may, if desired, extend beyond the sides of the housing M, as shown in Fig. 2, in order to make a greater amount of coal available to the action of the arm, however, the arm should not project such a distance beyond the housing as to require excessiv power to operate it or render it subject to stalling.

In similar manner, the arm 38 is relieved of a considerable portion of the weight of the head of coal in the bin by a disc-like plate 6| concentrically mounted with respect to the path describedby the end of the arm 33. The disc-like plate ti is supported above the arm 38 by a support member 82 extending through the hollow shaft 41% into the compartment 25 and rigidly secured in any suitable manner on the bottom of the bin is. Coal will enter beneath the plate 6| as far as its angle of repose, represented by the lines Z, Z in Fig. 4. Thus while practically the entire arm 38 is available for pushing coal into the zone .of action, of the screw conveyor 3!, the arm 38 is relieved of a considerable portion of the weight of the head of coal in the bin.

I claim:

1. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a longitudinally extending conveyor in said bin delivering to said opening, a guard over said conveyor, said guard providing lateral-material entrances from the bin to the space beneath said guard, said guard being arranged to preclude the material from reaching the zone of action of said conveyor through said lateral entrances when said material assumes its normal angle of repose, and means beneath said guard for effecting movement of material from said entrances into the zone of action of said conveyor.

2. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a material conveying screw in said bin delivering to said opening, a guard over said conveying screw, said guard providing lateral material entrances from the bin to the space beneath said guard, said guard being arranged to preclude the material from reaching the zone of action of said conveying screw through said lateral entrances when said material assumes its normal angle of repose, and means beneath said guard for effecting movement of material from said entrances into the zone of action of said conveying screw.

3. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a material conveying screw in said bin delivering to said opening, a guard over said conveying screw, said guard providing'lateral material entrances from the bin to-the space beneath said guard, said guard being arranged to preclude the material from reaching the zone of action of said conveying screw through said lateral entrances when said material assumes its normal angle of repose, a vertical rotary shaft beneath said guard, and arm-like means extending laterally from said shaft for effecting movement of material from said entrances into the zone of action of said conveying screw.

l. In a device for conveying solid material from'a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a material conveying screw in said housing delivering to said opening, said housing having upright side walls, said upright side walls each having an opening providing an entrance for admitting fuel from said bin to said housing, the vertical extent of said opening being such as to preclude the material from reaching the zone of action of said conveying screw when said material assumes its normal angle of repose, and means in said housing for effecting movement of material from said entrances into the zone of action of said conveying screw.

5. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a material conveying screw in said housing delivering to said opening, said housing having upright side walls, said upright side walls each having an opening providing an entrance for admitting fuel from said bin to said housing, the vertical extent of said opening being such as to preclude the material from reaching the zone of action of said conveying screw when said material assumes its normal angle of'repose, a vertical rotary shaft in said housing, and arm-like means extending laterally from said shaft for effecting movement of material from said entrances into the zone of action of said conveying screw.

6. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a material conveying screw in said housing delivering to said opening, said housing having a movable roof portion providing an adjustable opening for admission of material into the housing, said housing also being formed with lateral entrances, and means in said housing for effecting movement of material from said entrances into the zone of action of said conveying screw.

7. In a device for conveying solid material a from a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a material conveying screw in said housing delivering to said opening, said housing having a movable roof portion providing an adjustable opening for admission of material into the housing, said housing also being formed with lateral entrances, a vertical rotary shaft in said housing, and arm-like means extending laterally from said shaft for effecting movement of material from said entrances into the zone of action of said screw conveyor. 7

8. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a trough extending longitudinally within said housing and delivering to said opening, a material conveying screw insaid trough, said housing being formed with lateral entrances arranged to,

' in said housing and delivering to said opening, a

material conveying screw in said trough, said housing being formed with lateral entrances, a vertical'rotary shaft in said housing, and armlike means extending laterally from said shaft for effecting movement of material from said entrances into said trough.

10. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a material conveyor in said bin delivering to said opening, a. vertical rotary shaft adjacent said conveyor, arm-like mean extending laterally from said shaft for effecting movement of material from said bin into the zone of action of said conveyor, anda disc shaped guard concentric with the circle described by the end of said arm-like means for relieving said arm-like means of at least a portion of the weight of the head of material in the bin.

11. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a longitudinally extending sectional material conveyor within said bin delivering to said opening, a

guard overlying at least the greater portion of the length of said sectional conveyor, said guard being arranged to provide material entrances from the bin to the space beneath said guard, and means adjacent said sectional conveyor for effecting movement of material into the zone of action of said sectional conveyor. 7

12. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a centrally disposed longitudinally extending sectional screw conveyor in the bottom of said bin delivering to said opening, a transversely disposed longitudinally extending guard overlying at least the greater portion of the length of said sectional screw conveyor, said guard providing lateral material entrances from the bin to the space beneath said guard, said guard being arranged to preclude the material from reaching the Zone of action of the guarded portion of said screw conveyor through said lateral entrances when said material assumes its normal angle of repose, and means adjacent each section of said screw conveyor for effecting movement of material into the zone of action of said sectional screw conveyor.

from a bin, said bin having an opening in the lower portion of an upright wall thereof, a centrally dispossd longitudinally extending sec-, tional screw conveyor in the bottom of said bin delivering to said opening, a transversely disposed longitudinally extending guard overlying said sectional screw conveyor, a vertical rotary shaft adjacent each section of said screw conveyor, and arm-like means extending laterally from said shafts between said guard and said sectional screw conveyor for effecting movement of material into the zone of action of said sectional screw conveyor.

14. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a centrally disposed longitudinally extending sectional screw conveyor in the bottom of said bin delivering to said opening, a transversely disposed longitudinally extending guard overlying at least the greater portion of the length of said sectional screw conveyor, said guard providing lateral material entrances from the bin to the space beneath said guard, said guard being arranged to preclude the material from reaching the zone of action of the guarded portion of said screw conveyor through said lateral entrance when said material assumes its normal angle of repose, and means adjacent each section of said screw conveyor for eifecting movement of material into the zone of action of said sectional screw conveyor, said sectional screw conveyor being driven from its forward end, and a discennectible drive connection between the sections of said screw conveyor arranged to render a rearward section inoperative when said section encounters undue resistance.

15. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a centrally disposed longitudinally extending sectional screw conveyor in the bottom of said bin delivering to said opening, said sectional screw conveyor being driven from its forward end, a transversely disposed longitudinally extending shield overlying said sectional screw conveyor, a vertical rotary shaft adjacent each section of said screw conveyor, arm-like means extending laterally from said shafts between said shield and said sectional screw conveyor for effecting movement of material into the zone of action of said sectional screw conveyor, and a disconnection between the sections of said screw conveyor arranged to render a rearward section inoperative when said section encounters undue resistance.

16. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a housing within said bin communicating with said opening, a material-conveying screw in said housing delivering to said opening, said housing being formed with lateral entrances, a material-conveying screw operatively connected with and extending rearwardly from said first named screw, a transversely disposed longitudinally extending plate overlying said second named screw, and means associated with each of said screws for eifecting movement of material from the bin at each side of said housing and plate into the zone of action of said screws.

17. In a device for conveying solid material from a bin, said bin having an opening in the lower portion of an upright wall thereof, a material conveyor in said bin delivering to said opening, a vertical rotary shaft adjacent said conveyor, arm-like means extending laterally from said shaft for effecting movement of material from said bin into the zone of action of said conveyor, and a guard over said arm-like means covering a substantial portion of the area traversed by said arm-like means for relieving said arm-like means of at least a portion of the weight of the head of material in the bin, said arm-like means extending beyond the periphery of said guard and the end of said arm-like means describing a path during its movement circumscribing the periphery of said guard.

NATHAN M. LOWER. 

